package com.xinhuo.util;

import java.io.ByteArrayOutputStream;

public class BytesUtil {
	 
	private static String hexString = "0123456789ABCDEF";
 
	public static String stringToHexString(String strPart) {
 
		String hexString = "";
 
		for (int i = 0; i < strPart.length(); i++) {
			int ch = (int) strPart.charAt(i);
			String strHex = Integer.toHexString(ch);
			hexString = hexString + strHex;
		}
 
		return hexString;
 
	}
 
	/*
	 * 
	 * 将字符串编码成16进制数字,适用于所有字符（包括中文）
	 */
	public static String encode(String str) {
 
		// 根据默认编码获取字节数组
 
		byte[] bytes = str.getBytes();
		StringBuilder sb = new StringBuilder(bytes.length * 2);
 
		// 将字节数组中每个字节拆解成2位16进制整数
		for (int i = 0; i < bytes.length; i++) {
			sb.append(hexString.charAt((bytes[i] & 0xf0) >> 4));
			sb.append(hexString.charAt((bytes[i] & 0x0f) >> 0));
		}
 
		return sb.toString();
 
	}
 
	/*
	 * 
	 * 将16进制数字解码成字符串,适用于所有字符（包括中文）
	 */
	public static String decode(String bytes) {
 
		ByteArrayOutputStream baos = new ByteArrayOutputStream(bytes.length() / 2);
 
		// 将每2位16进制整数组装成一个字节
		for (int i = 0; i < bytes.length(); i += 2)
			baos.write((hexString.indexOf(bytes.charAt(i)) << 4 | hexString.indexOf(bytes.charAt(i + 1))));
		return new String(baos.toByteArray());
 
	}
 
	private static byte uniteBytes(byte src0, byte src1) {
 
		byte _b0 = Byte.decode("0x" + new String(new byte[] { src0 })).byteValue();
		_b0 = (byte) (_b0 << 4);
		byte _b1 = Byte.decode("0x" + new String(new byte[] { src1 })).byteValue();
		byte ret = (byte) (_b0 | _b1);
 
		return ret;
 
	}
 
	public static byte[] hexString2Bytes(String src) {
 
		byte[] ret = new byte[6];
		byte[] tmp = src.getBytes();
		for (int i = 0; i < 6; ++i) {
			ret[i] = uniteBytes(tmp[i * 2], tmp[i * 2 + 1]);
		}
 
		return ret;
 
	}
 
	/**
	 * 
	 * Convert byte[] to hex
	 * string.这里我们可以将byte转换成int，然后利用Integer.toHexString(int)来转换成16进制字符串。
	 * 
	 * @param src
	 *            byte[] data
	 * 
	 * @return hex string
	 */
	public static String bytesToHexString(byte[] src) {
 
		StringBuilder stringBuilder = new StringBuilder("");
 
		if (src == null || src.length <= 0) {
			return null;
		}
 
		for (int i = 0; i < src.length; i++) {
			int v = src[i] & 0xFF;
			String hv = Integer.toHexString(v);
			if (hv.length() < 2) {
				stringBuilder.append(0);
			}
			stringBuilder.append(hv);
		}
 
		return stringBuilder.toString();
 
	}
 
	/**
	 * 
	 * Convert hex string to byte[]
	 * 
	 * @param hexString
	 *            the hex string
	 * 
	 * @return byte[]
	 */
	public static byte[] hexStringToBytes(String hexString) {
 
		if (hexString == null || hexString.equals("")) {
			return null;
		}
 
		hexString = hexString.toUpperCase();
		int length = hexString.length() / 2;
		char[] hexChars = hexString.toCharArray();
		byte[] d = new byte[length];
		for (int i = 0; i < length; i++) {
			int pos = i * 2;
			d[i] = (byte) (charToByte(hexChars[pos]) << 4 | charToByte(hexChars[pos + 1]));
		}
 
		return d;
 
	}
 
	/**
	 * 
	 * Convert char to byte
	 * 
	 * @param c
	 *            char
	 * 
	 * @return byte
	 */
	private static byte charToByte(char c) {
		return (byte) "0123456789ABCDEF".indexOf(c);
	}
 
}
